/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/PBDTriangleMeshCollisions.h
Because they are opposite colors with a shared contour index. This will cause repulsion forces to attract and fix the intersection. NOTE: We flip normals if ANY of the TriVertColors are opposite the PointColor or if the TriColor (used for thin regions is flipped). This does a better job for thin features than only flipping normals if ALL TriVertColors are opposite.
static bool ShouldFlipNormal &40; const FGIAColor & Color0, const FGIAColor & Color1 &41;